This invention relates to pressure responsive valves of the kind which are operable to vent a space to atmosphere when the pressure within that space rises above a predetermined level. One application of such valves is in relation to cooking vessels such as pressure cookers, and it will be convenient to hereinafter describe the invention with particular reference to that example application.
Pressure relief valves as used in cooking vessels prior to the present invention suffer a variety of problems. Particularly prevalent problems are complex construction and ineffective operation. Operation may be ineffective because of the valve sticking, and that can lead to dangerous situations. Furthermore, a great many prior valves automatically reset to the closed position so there is no visible sign of an excessive pressure condition having been reached, and that leads to the possibility of the excessive pressure condition being repeated. Valves which do not reset automatically are generally inconvenient to restore to an operation condition, and in some cases at least one part may become completely detached from the associated vessel when the valve opens.
It is an object of the present invention to provide a valve of the foregoing kind which is of relatively simple construction and which is effective and convenient in use. It is a further object of the invention to provide a cooking vessel having the improved valve as a pressure relief valve.